Gas discharge tube comprising a number of electrodes united to form a group and having the form of characters

ABSTRACT

The digit-electrodes of a number of character-shaped electrodes of electrode groups placed side by side in a common envelope are shaped as punched strips, stacked one on the other.

United States Patent Inventor Adrianus Anthonius Maria HendriksEmmasingel, Eindhoven, Netherlands App]. No. 776,471 Filed Nov. 18, 1968Patented Feb. 16, 1971 Assignee U.S. Philips Corporation New York, N.Y.Priority Dec. 6, 1967 Netherlands 6716506 GAS DISCHARGE TUBE COMPRISINGA NUMBER OF ELECTRODES UNITED TO FORM A GROUP AND HAVING THE FORM OFCHARACTERS 4 Claims, 11 Drawing Figs.

U.S. Cl 313/l09.5, 313/210 Int. Cl. H0lj 61/66, HOlk 7.04

[50] Field olSearch 313/1095, 108, 210; 315/169 [56] References CitedUNITED STATES PATENTS 2,520,513 8/1950 Sereno 313/109.5X 3,361,9201/1968 Rosenfeld 1. 313/1095 3,418,509 12/1968 Frouws et a1. 313/1095Primary Examiner Roy Lake Assistant ExaminerDavid OReilly AnomeyFrank R.Trifari ABSTRACT: The digit-electrodes of a number of charactershapedelectrodes of electrode groups placed side by side in a common envelopeare shaped as punched strips, stacked one on the other.

PATENTEU Fan Si n 3564;324- susnlur's PIC-5.3a

FIGAa m 5 mm R D NN E H A s U N M R D A BY M /Q AGE.PAIENTEU-FE'BI-EIHYI sum 3 [1F 3 Flew v INVENTOR. ADRIANUS A.M.HENDRIKSGAS DISCHARGE TUBE COMPRISING A NUMBER OF ELECTRODES UNITED TO FORM AGROUP AND HAVING THE FORM OF CHARACTERS The invention relates to a gasdischarge tube comprising a number of electrodes united to form a groupby stacking, having the form of legible characters and arranged oppositeto an anode.

In known tubes employing electrodes which are formed as legiblecharacters and are united to form a group with the interposition ofinsulating plates, a group with the associated remaining electrodes isalways arranged in a separate envelope. For reproducing numbers or wordsa number of such tubes are arranged beside and/or above each other.

The drawback is that a large number of separate tubes have to beprovided so that the mutual distance of the characters represented bythe tubes is comparatively large which hampers the reading. Moreover the'use of a number of separate tubes is expensive. v

The above-mentined drawbacks are strongly reduced by using a similar gasdischarge tube which, according to the invention, comprises a number ofuniform electrode groups which are arranged beside each other in acommon envelope, the corresponding electrodes of all the groups lying inone plane and the corresponding characters of all the groups being atthe same time connected together to form a strip, the electrodes locatedin different planes being stacked one on the other with theinterposition of correspondingly shaped strips of insulating material.

Theassembly is inserted in one envelope having an elongated crosssection, which envelope may be provided on either end with pinchesthrough which the current supply wires for the various electrodes extendin a vacuum-tight manner.

The invention will now be described with reference to the accompanyingdrawing, in which:

FIG, 1 shows a perspective view of a tube according to the invention,

FIGS. 2, 3, 4, 5, 6, 7 and 8 show components of the electrode system ofthe tube,

FIG. 9 is a partial longitudinal cross'sectional view of a tubeaccording to the invention, and

FIG. 10 is a longitudinal cross-sectional view of another embodiment,and

FIG. 11 is a plan view of FIG. 10, partly broken away.

Referring now to FIG. 1, reference numeral 1 denotes the glass envelopeof the tube which has an elongated cross section and is closed at itsend by pinches 2 and 3. The supply conductors for an auxiliary electrodeand for the strips to which the character-shaped electrodes areconnected extend, for example, through the pinch 2, while the currentconductors for the anodes associated with the various groups extendthrough the pinch 3.

The set of electrodes arranged in the envelope 1, is obtained bystacking the components as follows:

On an insulating strip 4 (FIG. 2) consisting of mica artificial mica orceramic material, a narrow strip 5 is laid (FIG. 3) which in this casecomprises l lugs 6 which are bent at right angles so that the lugs 6project upwards. On this assembly an insulating strip 7 is laid (FIG. 4)in which apertures 8 are provided through which the lugs 6 extend. Anodeplates 9, in this case II), are secured to the strip 7 in such mannerthat they are insulated from each other, and are each provided with acurrent supply wire 13. The anode plates 9 comprise an aperturecorresponding to the apertures 8 so that the lugs 6 projects through theanode plates 9 in an insulated manner. In fact, the lugs 6 serve asdecimal points.

On the strip 7 with the anodes 9, an insulating strip 14 (FIG. is placedin which apertures 15 are provided which correspond to the anodes 9 andare separated from each other by transverse strips 15.

The characterlike electrodes are in this case shaped as digits 0-9.Figure 6 shows a strip 16 of the digits, in which the digits 0 arepunched in such a manner that said digits are still connected to thestrip 16 with narrow strips 17. The strip 16 comprises in this case l0electrodes 0, which are separated by transverse strips 18. On the strip16 again a strip 14 is provided on which a strip 16 having digits I islaid, and so on, alternately strips 14 and digit strips 16 with theremaining digits 29. As shown in FIG. 7, the strips 18 are forcedthrough alternately to one and to the other side. As a result of this,gapshaped spaces are formed between the insulating strips 14 and thedigit strips 16 so that metal sputtering from the electrodes cannotcause shortcurcuit between the digit strips 16.

A gauze electrode 19 is provided on the uppermost perforated insulatingstrip 14 and is also provided with a current supply conductor (12 inFIG. 1) and serves to check blackening of the tube by sputtering metal.After a mercury holder 20 is secured to the gauze 19 the set thusobtained by stacking strips and digit strips is slid into a glass tube 1(FIG. 9) having an elongate cross section, after which the tube 1 isheated at the ends and sealed by means of a pinch 2, 3. The tube isprovided, for example, on its rear side, with an exhaust tube (notshown). After evacuating and filling with a suitable gas the tube issealed.

The tube shown partly in cross section in FIG. 9 can reproduce a numberof IO digits.

The lighting up of a digit is obtained by setting up zero potential atthe digit strip in question and a positive potential of, for examplevolts, at the associated anode. In order to cause several digits tolight up they are intermittently caused to light up with a sufficientlyhigh frequency, so as to give a permanent lighting-up impression. Thedigit strips which do not light up and the gauze 19 are kept at anintermediate potential of, for example, 65 volts. In this case the gauze19 cannot be connected to the anode 9 as in known digit tubes, sincethese anodes have to remain independent of each other.

FIGS. 10 and 11 show another embodiment in which the anodes 23 are inthe form of a U, so that the transverse strips 15 and 18, respectively,of the mica strips 14, and the digit strips 16 may be omitted whichsimplifies the manufacture and assembling. Since the'digit strips 22 arekept at some distance from each other, by the insulating strips 21,short circuit of the digit strips by metal deposits is avoided as suchwithout forced-through strips as shown in FIG. 7 being necessary. Theupright edges of the anodes 23 are kept separated by insulating plates24. Since equal digits need not be mounted separately but can be cut asas a punched strip of a given length and be stacked, the manufacture ofsuch a digit tube which thus contains totally I00 digits, is muchsimpler and cheaper than of 10 separate tubes having each 10 digits inwhich the decimal point usually is also formed as a separate tube. Anadvantage of a tube according to the invention is furthermore that thedecimal point can be placed between the digits. Although a tube has beendescribed of 10 digits located beside each other, this number may bearbitrarily chosen. Alternatively, the electrodes may be formed asletters instead of digits, while a number of the described tubes may bearranged above each other. The characters are close together since nopartition walls are necessary as is the case when separate tubes areplaced side by side.

Iclaim:

1. A gas discharge tube comprising an elongated envelope, a plurality ofstacks of character-shaped electrodes united to form a group andpositioned opposite to an anode, said electrode stacks being arrangedbeside each other in said envelope with corresponding electrodes of allthe groups lying in one plane and the corresponding electrodes of allthe groups being at the same time connected together in the form of astrip, the electrodes located in different planes being stacked one onthe other with the interposition of correspondingly shaped strips ofinsulating material.

2. A gas discharge tube as claimed in claim 1, wherein the anodes of thestacks are arranged so as to be insulated from each other and are eachprovided with'a current supply conductor.

3. A gas discharge tube as claimed in claim 1 wherein the anodes havethe form of a U, the upright edges constituting the'separation betweenthe said several electrode stacks.

said electrodes light up, and means to apply to the remaining electrodesan intermediate positive potential whereby said latter electrodes do notlight up.

1. A gas discharge tube comprising an elongated envelope, a plurality ofstacks of character-shaped electrodes united to form a group andpositioned opposite to an anode, said electrode stacks being arrangedbeside each other in said envelope with corresponding electrodes of allthe groups lying in one plane and the corresponding electrodes of allthe groups being at the same time connected together in the form of astrip, the electrodes located in different planes being stacked one onthe other with the interposition of correspondingly shaped strips ofinsulating material.
 2. A gas discharge tube as claimed in claim 1,wherein the anodes of the stacks are arranged so as to be insulated fromeach other and are each provided with a current supply conductor.
 3. Agas discharge tube as claimed in claim 1 wherein the anodes have theform of a U, the upright edges constituting the separation between thesaid several electrode stacks.
 4. A circuit arrangement for operating agas discharge tube as claimed in claim 1, including means tointermittently apply zero potential and a positive potential,respectively, electrodes in each group relative to the anode for saidgroup whereby said electrodes light up, and means to apply to theremaining electrodes an intermediate positive potential whereby saidlatter electrodes do not light up.